.net如何开发限速下载的客户端

zyip 2009-02-11 09:59:20

像bt 迅雷这样的软件在下载的时候可以指定每秒最大多少k怎么实现的阿
.net如何实现
c/c++实现也行

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zyc_piaoling 2011-06-24

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我也要做这类的。可惜都找不到。希望能学习下

mbtw_1984 2009-03-20

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没这么简单的，大家要认真回答，不能浪费别个的感情

浪子-无悔 2009-02-18

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呵呵，我ye没做过！友情帮顶..顺便学习。。

jin20000 2009-02-18

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LS的都说的没错了啊,就是流读取限制一下就OK了

wangping_li 2009-02-18

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主要是FileStream类.找到一个示例，可以参考



       //   输入参数：

        //   _Request: Page.Request对象

        //   _Response:   Page.Response对象

        //   _fileName:   下载文件名 

        //   _fullPath:   带文件名下载路径

        //   _speed   每秒允许下载的字节数   

        public static bool ResponseFile(HttpRequest _Request, HttpResponse _Response, string _fileName, string _fullPath, long _speed)

        {

            try

            {

                FileStream myFile = new FileStream(_fullPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);

                BinaryReader br = new BinaryReader(myFile);

                try

                {

                    _Response.AddHeader("Accept-Ranges", "bytes");

                    _Response.Buffer = false;

                    long fileLength = myFile.Length;

                    long startBytes = 0;



                    int pack = 10240;   //10K   bytes   

                    //int   sleep   =   200;   //每秒5次   即5*10K   bytes每秒   

                    int sleep = (int)Math.Floor(1000 * pack / _speed) + 1;

                    if (_Request.Headers["Range"] != null)

                    {

                        _Response.StatusCode = 206;

                        string[] range = _Request.Headers["Range"].Split(new char[] { '=', '-' });

                        startBytes = Convert.ToInt64(range[1]);

                    }

                    _Response.AddHeader("Content-Length", (fileLength - startBytes).ToString());

                    if (startBytes != 0)

                    {

                        _Response.AddHeader("Content-Range", string.Format("   bytes   {0}-{1}/{2}", startBytes, fileLength - 1, fileLength));

                    }

                    _Response.AddHeader("Connection", "Keep-Alive");

                    _Response.ContentType = "application/octet-stream";

                    _Response.AddHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(_fileName, System.Text.Encoding.UTF8));



                    br.BaseStream.Seek(startBytes, SeekOrigin.Begin);

                    int maxCount = (int)Math.Floor((fileLength - startBytes) / pack) + 1;



                    for (int i = 0; i < maxCount; i++)

                    {

                        if (_Response.IsClientConnected)

                        {

                            _Response.BinaryWrite(br.ReadBytes(pack));

                            Thread.Sleep(sleep);

                        }

                        else

                        {

                            i = maxCount;

                        }

                    }

                }

                catch

                {

                    return false;

                }

                finally

                {

                    br.Close();

                    myFile.Close();

                }

            }

            catch

            {

                return false;

            }

            return true;

        }

调用示例：
Page.Response.Clear();
bool success = ResponseFile(Page.Request, Page.Response, "filename", @"C:\download.date", 1024000);
if(!success)
Response.Write("下载文件出错！");
Page.Response.End();

liucuiqiang 2009-02-18